The Google OpenID API lets third-party web sites and applications let visitors sign in using their Google user accounts. The OpenID standard allows users to nor have to set up separate login accounts...

From their site: Developers of installed applications have the option of using a programmatic login method to access Google services protected by user login. An installed application is installed on...

From their site: A REST-based API with methods for uploading, converting, editing, deleting, and searching documents. Using the API, you can use Scribd as a back-end for an application that needs to...